Present day surgically implantable human breast prosthesis is often recognized as having originated with the implant disclosed in Cronin U.S. Pat. No. 3,293,663 dated Dec. 27, 1966, in which a silicone gel-filled flexible container approximating the shape of the human breast is provided on the back wall with a layer of porous material, preferably a fabric of polyester fibers commonly sold under the trademark Dacron, into which tissue can grow so as to anchor the prosthesis to the chest wall.
It was subsequently demonstrated, as reported in Williams, J. E.: Experiences with a large series of silastic breast implants. Plast. and Reconstr. Surg. 49:253, 1972, that such anchorage was unnecessary because the fibrous capsule itself is ultimately sufficiently strong to anchor the implant.
In U.S. Pat. No. 3,665,520, dated May 30, 1972, to Perras and Papillon, a surgically implantable breast prosthesis is disclosed in which the back wall of the container is reinforced by a bio-compatible fabric mesh material and the prosthesis is secured to the chest wall of the patient by means of a strip of felt-like material, such as Dacron. The Dacron felt strip is located around the periphery of an axillary prolongation and across the top portion of the back wall of the container.
Somewhat similar means for holding breast prostheses in place is disclosed in Perras U.S. Pat. No. 3,681,787, dated Aug. 8, 1972. In this patent, the container is filled with silicone gel which is more viscous around the outer periphery of the container than in the center of the container, and anchoring is provided by a strip of porous material, such as corrugated Dacron fabric, the strip extending across the top and more than half way around the periphery, but leaving the bottom edge unattached to the chest wall. These prostheses were usually placed prepectorally beneath the mammary gland. Their usage did not appear to become widespread owing, perhaps, to the fact that the ridged back not infrequently became palpable, according to Papillon, J.: Pros and Cons of Subpectoral Implantations; Clinics in Plastic Surgery, Vol. 3, No. 2, April 1976.
The prior art, in other words, relates to implants and means physically attached to the implants for improving their performance.